The prior art is already aware of using a hardenable liquid for forming a stitch or the like in a stack of paper sheets. That is, the concept of gluing sheets together by means of piercing the sheets with a hollow needle carrying a glue or the like is already known. Thus, the piercing of holes in sheets and filling the holes with a hardenable liquid, such as an adhesive or the like, is shown in U.S. Pat. Nos. 3,475,249 and 3,814,654 and 3,993,523 and British Pat. No. 893,375. The aforesaid U.S. Patents show the use of a needle for applying an adhesive to a pierced hole in sheets which are to be secured together by the adhesive. Further, some of the aforesaid patents show the use of a hollow needle which does the piercing and depositing of the glue or adhesive, in one motion. Another prior art example of utilizing a hollow needle and a hardenable liquid for securing sheets together is seen in U.S. Pat. No. 2,557,668, but this patent is only disclosing the formation of a variation for a sewing machine in that it applies a hardenable liquid in an extruding process for binding materials together. Finally, U.S. Pat. No. 2,817,513 shows a collating machine for sheets which it mentions can be stapled or glued together though it does not disclose any teaching for the gluing process.
The present invention differs from the prior art in that it provides a method and apparatus for stitching or securing sheets of paper together by a concept of piercing holes into the sheets and filling the holes with a hardenable liquid, all while the sheets are moving at a non-stop and continuous speed and with the sheets being positioned in sequential stacks all moving through the stitching apparatus in the non-stop process. Further, in this concept, sheets can be stitched either with the in-line stitching arrangement or in the cross-stitching arrangement, both of which are disclosed herein.
Additionally, the present invention provides an arrangement whereby the sheets to be stitched together can be continuously moved through two whirling members with one member thereof carrying the hollow needles and supplying the hardenable liquid. Still further, the hollow needles on the one member can be positioned in desired circumferential positions on the member for providing the desired stitch pattern on the sheets. In that regard, the circumference of the member is related in length to the spacing of the center lines of the stacks of sheets to be stitched together, such that the desired stitching patterns or locations can be achieved in the continuous process being described and disclosed herein. In actuality, the circumference of the one member is equal to the pitch or distance between the center lines of the stacks of sheets times a multiple of a whole number. That is, the so-called pitch of the moving member supporting the sheets times a multiple of a whole number is equal to the circumference on which the hollow needles are located.
Still further, the present invention provides a method and means for supplying the hardenable liquid from a single location or source of supply even though the applicator needles are moving in a circular path around that stationary or single supply source location
Accordingly, the present invention provides for the improvement upon the prior art, and it is susceptible to stitching either in the in-line or cross-stitch arrangement, and provides for the desired continuous motion which is the required high speed process for today's graphic arts industry. Also, the process and apparatus of this invention lends itself readily to a selectivity or changing of the stitching pattern for both the in-line and cross-stitch arrangement, all in a simplified and expeditious manner and one which can be accomplished on the job site. A cover is glued on, to form a book or magazine.
Other objects and advantages and differences over the prior art will become apparent upon reading the following description in light of the accompaying drawings.